Crystalline alumino-silicate zeolites containing polyvalent metal cations

ABSTRACT

A hydrocarbon conversion catalyst composition, useful for paraffin-olefin alkylation, can comprise a three dimensional crystalline zeolite molecular sieve having a pore size large enough to adsorb 2,2,3-trimethylpentane and having a composition expressed in terms of mole ratios of oxides as A(I2O);b(IIO):c(III2/3O):d(IV1/2O)Al2O3:eSiO2 wherein I represents a monovalent metal cation; II represents a divalent metal cation; III represents a trivalent metal cation; IV represents a tetravalent cation; a has a value of from zero to 0.15; b has a value of from zero to 0.75; c and d each have values of from zero to 1; e has a value of from 2 to 20; with the proviso that when e has a value of from 2 to 3, the value of ((b+c) 0.75 to 1 and d O; and with the proviso that when e has a value of &gt; 3 to 4, the value of (b+c+d) 0.6 to 1.0; and with the further proviso that when e has a value of &gt; 4 to 20, the value of (b+c+d) 0.25 to 1.0. In one embodiment said zeolite contains less than about 60 percent of its maximum OH exhibiting infrared absorption in the region of 3,480 to 3,670 cm. 1; however in a slurry-reaction process the preferred catalysts have been activated at a temperature in the range of 400*-500*C. and contain about said maximum OH absorption. In the above catalyst, protons and/or ammoniumions can be present to preserve electronic equivalency. The degree of conversion of olefins and paraffins to saturated products can be increased by incorporation into the catalyst of a halide adjuvant containing bromine, chlorine or fluorine. One preferred catalyst can be represented, by the above formula as 0.1(I2O):0.7(III2/3O):Al2O3:4.7SiO2 where I is Na and III is a trivalent rare earth metal, such as Ce 3. More precisely, this catalyst can be represented as 0.1(Na2O):0.2(H2O):0.7(III2/3O):Al2O3:4.7SiO2.

United States Patent 1191 Kirsch et al.

[451 Oct. 1, 1974 ['5 CRYSTALLINE ALUMINO-SILICATE ZEOLITES CONTAINING POLYVALENT METAL CATIONS [75] Inventors: Francis William Kirsch, Wayne;

David S. Barmby, Media; John D. Potts, Springfield, all of Pa.

[73] Assignee: Sun Oil Company of Pennsylvania, Philadelphia, Pa.

[22] Filed: Dec. 22, 1971 [21] Appl. No.: 211,040

Related US. Application Data [63] Continuation-in-part of Ser. Nos. 581,129, Aug. 25, 1966, abandoned, and Ser. No. 715,998, March 26, 1968, Pat. No. 3,624,173, and Ser. No. 716,190, March 26, 1968, and Ser. No. 749,714, Aug. 2, 1968, abandoned, and Ser. No. 823,656, May 12, 1969, and Ser. No. 830,687, June 5, 1969, Pat. No. 3,655,813, and Ser. No. 840,110, June 16, 1969, abandoned, and Ser. No. 34,209, May 4, 1970, Pat. No. 3,706,814, and Ser. No. 114,061, Feb. 9, 1971.

[52] US. Cl 252/455 Z [51] Int. Cl Blj 11/40 [58] Field of Search 252/455 Z; 423/112 [56] References Cited UNITED STATES PATENTS 3,251,902 5/1966 Garwood et al. 260/683.64

3,277,018 /1966 Plank et al 252/451 3,324,048 6/1967 Plank et al. 252/455 Z 3,367,885 2/1968 Rabo et al 252/455 Z 3,402,996 9/1968 Maher et al.... 252/455 Z 3,437,604 4/1969 Michalko 252/455 Z 3,549,557 12/1970 Bolton et a1 252/455 Z Primary Examiner-C. F. Dees Attorney, Agent, or Firm-George L. Church; .1. Edward Hess; Barry A. Bisson 57 ABSTRACT A hydrocarbon conversion catalyst composition, useful for paraffin-olefin alkylation, can comprise a three dimensional crystalline zeolite molecular sieve having a pore size large enough to adsorb 2,2,3- trimethylpentane and having a composition expressed in terms of mole ratios of oxides as a(l O);b(llO):c(Ill O):d(IV,, O)Al O :eSiO

wherein 1 represents a monovalent metal cation; 11 represents a divalent metal cation; 111 represents a trivalent metal cation; 1V represents a tetravalent cation; a has a value of from zero to 0.15; b has a value of from zero to 0.75; c and d each have values of from zero to 1; e has a value of from 2 to with the proviso that when e has a value of from 2 to 3, the value of ((b+c)=0.75 to 1 and d=O; and with the proviso that when e has a value of 3 to 4, the value of (b-l-e-+d)=0.6 to 1.0; and with the further proviso that when e has a value of 4 to 20, the value of (b+c+d)=0.25 to 1.0. In one embodiment said zeolite contains less than about 60 percent of its maximum OH exhibiting infrared absorption in the region of 3,480 to 3,670 emf; however in a slurry-reaction process the preferred catalysts have been activated at a temperature in the range of 400-500C. and contain about said maximum 01-1 absorption. In the above a lxstzrt t as and/Or am o m mis anb P e ent to preserve electronic equivalency. The degree of conversion of olefins and paraffins to saturated products can be increased by incorporation into the catalyst of a halide adjuvant containing bromine, chlorine or fluorine. One preferred catalyst can be represented, by the above formula as 0.1(I 0):0.7(111 O):A1 O :4.7Si0

where I is Na and 111 is a trivalent rare earth metal, such as Ce. More precisely, this catalyst can be rep resented as 0.1(Na O):0.2(H O):0.7(11I O):A1 O :4.- 7SiO 13 Claims, No Drawings CRYSTALLINE ALUMINO-SILICATE ZEOLITES content of cations of Celll, has been indicated by the CONTAINING POLYVALENT METAL CATIONS symbol Ce Y, the more precise symbol would be Ce'"I-lNaY, indicating that minor amounts of sodium CROSS REFERENCES L can be retained in the zeolite and that electronic equiv- APPLICATIONS 5 -alency is maintained by protonic sites. Even more precision in catalyst definition can be provided by The present application is a continuation-in-part of means of the formulas utilized herein (e.g., 0.1Na0:0.4-

all of the following copending applications, of the pres- H 0:05Ce 0:Al O :4.5SiO

ent inventors, Francis William Kirsch, David 5. As 1S discussed in greater detail in copending applica- Barmby, and John D. Potts: tion Ser. No. 716,190, it is sometimes advantageous to Serial No Filing Date Title 581.129 8-25-66 Process for Paraffin-Olefin Alkyla- (Now Abandoned) tion 715,998 3-26-68 Gd Zeolite and Hydrocarbon Conver- (Now U.S. 3,624,173, issued sion Process with Gd Zeolite Catalyst 11-30-71) 716,190 3-26-68 Process for Parafi'in Olefin Alkylation 749,714 8-2-68 Dy Zeolite and Hydrocarbon Con- (Now Abandoned) version Process with Dy Zeolite Catalyst 823,656 5-12-69 Paraffin-Olefin Alkylate Composition 830,687 6-5-69 Continuous Alkylation Process (now U.S. 3,655,813 issued 4-11-72) 840,110 6-16-69 Process for Producing Gasoline (Now Abandoned) Blending Components 34,209 5-4-70 Continuous Process for Producing (now U.S. 3,706,814 issued 12-19-72) Gasoline Blending Components 1 14,061 2-9-71 Process for Producing Gasoline Blending Components The disclosure of allot the zfijave-eitaeafmi'ifig eafiirdiiheaeiivanon such that the activated catalyst applications is hereby incorporated in the present apcontains about V4 to 2 mole of bound water for each plication. atom of exchanged polyvalent metal (e.g., in a cerium In particular, paraffin and olefin feed components Y zeolite alkylation catalyst, in the range of 0.8-1.2 which can be converted to gasoline blending compomolecules of water will be evolved for each atom of cenents by use of catalysts of the present invention are rium, upon ignition at 1,800F.). lt can also be advantadisclosed in the above-cited copending applications. geous in some cases to control the activation so that the The said copending applications, (especially Ser. No, activated zeolite catalyst contains less than about 60 581,129; 715,998 and 716,190) also disclose zeolites percent of its maximun OH exhibiting infrared absorpof the present invention, such as the substantially anhy- 40 tion in the region of 3480-3670 cm. This requiredrous acidic crystalline alumino-silicate zeolites whichment can be fulfilled, for example, by utilizing the have a low alkali metal content and a high content of 600F. activated catalysts described in our application cations of a polyvalent metal. I Ser. No. 716,190.

The processes disclosed in the said patent applications for activation, hydration and regeneration of BACKGROUND OF THE INVENTION aged" zeolite catalysts can also be useful means of im- This invention relates to the production of normally proving the commercial utility of our zeolites, particuliquid, saturated hydrocarbons, useful in gasoline larly for regeneration of aged catalysts which have blending, by reacting isoparaffins with olefins in liquid been used to convert paraffin and olefin feed compophase in the presence of a substantially anhydrous crysnents to gasoline blending components. talline alumino-silicate zeolite, and to means of prepar- M W 'ing such zeolites. In an of our prevlously cited apphcatlons In U.S. Pat. No. 3,549,557, a zeolite which contained .581129) we disclose a process for the production exchanged cations of polyvalent metals was defined as of highly saturated alkylate ,from monoolefins which :containing its maximum 01-! exhibiting infrared absorprequires not only a catalyst with a large number of acid tion in the region of 3,480 to 3,670 l when Sites of suffimint strength for hynde transfer P thermally removable OH content of a given molecular which also utilizes conditions which favor hydride sieve is fully developed (Len is at its maximum) transfer, such as introducing the olefin to the reactor in This maximum was further defined as being attained P liquid Phase and fmlmate adrfllxture "P C4C6 when the zeolite has been heated to between 300C isoparaffin and controlling the addition of said olefin and This definition is used in the present appli such that the concentration of unreacted olefin in the cation reaction mixture is maintained at a low level- It was further stated that at least 40 percent of these In general, the Preferred catalysts in this Process are OH can be thermally removed by heating the zeolite in obtained from a polyvalent metal cation containing zeth range f 550C t 800C, F purposes of the pres- Olite which iS activated y t g) to remove "t 65 ent application, it is applicants definition that this re- Of Water 001116111 (and, if P n nitrogen quirement for removal of at least 40 percent of these pounds). Although in some of these applications a pre- 01-1 is met when the zeolite has lost 40 weight percent ferred catalyst, an activated Y zeolite having a high of the water content at said maximum and thatazeolite which has been heated to 300C, or higher, (572F contains no more than said maximum of these OH. Therefore, the requirement that a zeolite contain less than about 60 percent of its maximum OH exhibiting infrared absorption in the region of 3,480 to 3,670 cm is defined herein as requiring that the zeolite has total water, as determined by weight, loss on ignition (LOI), that is no more than 60 percent of the total water which the zeolite had after heating for 60 minutes at 300C. In Table 4 hereof, (which is taken from our Ser. No. 716,190) the column headed percent max OH is such a calculation made from the reported total H O, obtained by ignition analysis.

Thus, Table 4 describes catalysts of the previously referred to chemical formulae and which, by definition, exhibit less than 40 percent (e.g. Run No. E-7) and less than 60 percent (Run No. E-9) of said maximum OH.

These results are summarized below:

A zeolite similar in preparation to E-7, except that it had been activated for 2 hours at 600C. (and an estimated LOI of about 2.5i0.2 percent), was used as the catalyst in the alkylation run in Example XIII (hereinafter) which produced 128.5 percent of C parafiin (based on olefin charged). Table 23 herein provides additional analytical data on this alkylation product.

A more precise correllation (or definition) of the maximum OH exhibiting infrared absorption in the re gion of 3,480-3,670 Cm is that this maximum corresponds to the value at 300C in the H for Ce column of Table 4 herein. The requirement that a catalyst contain less than about 60 percent of said maximum is met when the H 0 for Ce" has decreased by about 40 percent or more.

This correllation or definition can be seen in the following Table (taken from the Table 4.data):

% Max OH Run No. Temp. C. H O for Ce E- 300 0.136 100 E- 400 0.102 75 E-() 500 0.075 55 5-7 600 0.046 34 E-8 700 0.037 27 5-9 700 0.007 V 5 SUMMARY OF THE INVENTION to 0.75; c and d each have values of from zero to l; e has a value of from 2 to 20, with the proviso that when e has a value of from 2 to 3, the value of (b-l-c)=0.75 to l and 11%); and with the proviso that when e has a value of 3 to 4, the value of (b+c-l-d)=0.6 to 1.0; and with the further proviso that when 2 has a value of 4 to 20, the value of (b-1-c+d)=0.25 to 1.0. In one embodiment said zeolite contains less than about 60 percent of its maximum OH exhibiting infrared absorption in the region of 3,480 to 3,670 cm. (which can be achieved by activation at about 600C or higher); however in a slurry-reaction process the preferred catalysts contain about said maximum OH absorption and have been activated at a temperature in the range of about 400-500C. In the above catalyst protons and/or ammonium ions can be present to preserve electronic equivalency.

The degree of conversion of olefins and paraffins to saturated products can be increased by incorporation into the catalyst of a halide adjuvant containing bro- '3 percent by weight of sodium;

b. further exchanging the ammonium-exchanged zeolite with a solution comprising rare earth metal ions until the zeolite contains, on an ignited basis, at least 7 percent by weight of rare earth metal ions;

0. heating the zeolite to a temperature in the range of 300C. until there is substantially no further loss of sorbed water, and

d. subjecting the zeolite to a temperature in the range of 300-700C (more preferred 320-600C.) in the presence'of a gas or under reduced pressure until the desired OH adsorption is obtained, generally until substantially no further evolution of associated water occurs.

In one embodiment, in the catalyst composition .of the above formula, the coefficient a can have a value of from zero to 0.08 and e can have a value of from 4 In another embodiment, the zeolite can contain less than 40 percent of its maximum OH exhibiting infrared absorption in the region of 3,480 to 3,670 emf.

In another embodiment, when e has a value of 3 to 4, the value of (b-l-c-1-d)=0.6 to 0.85; and when e has a value 4 to 20, the value of (b+c+d)=0.45 to 0.75;

An especially valuable catalyst which can be prepared by this process comprises Ce, Gd or a mixture of Gd and Ce as the exchanged metal ions. One preferred catalyst can be represented by the above formula as a)l O):c(III O);Al O :eSiO where a is about 0.1, I is Na, 0 is about 0.7, III consists essentially of rare earth metals and e is about 4.7 (the zeolite framework being Type Y).

FURTHER DESCRIPTION This invention relates to crystalline alumino-silicate zeolites containing polyvalent metal cations (e.g., cations of cerium) and having a low content of monovalent metalcations (e.g., Na Such zeolites, when activated can be useful for many hydrocarbon conversion reactions (cg, alkylation. cracking, isomerization, hydroisomerization). I

Our co-pending application Ser. No. 716,190 relates to a process for the preparation of an olefin-paraffin alkylate comprising:

a. contacting C -C monoolefin in admixture with C -C isoparaffin having a tertiary carbon atom, at a temperature below the critical temperature of the lowest boiling hydrocarbon reactant and at a pressure such that the reactants are in liquid phase, with a substantially anhydrous acidic crystalline alumino-silicate zeolite, and

b. stopping such contacting after substantial alkylation has occurred but before the weight rate of production of unsaturated hydrocarbon becomes greater than the weight rate of production of saturated hydrocarbon. The zeolites according to the present invention when activated, e.g., are in substantially anhydrous acidic form, and preferably when substantially free from nitrogen compounds, are particularly suitable for use in the above process.

Acidic crystalline alumino-silicate zeolites in hy- I drated form can in general be chemically characterized by the empirical formula M,(AlO ),(SiO ),,.(I-I O) Where M is H and/or an equivalent valence of metal cations and x, y and z are integers, the ratio x/y being usually from 1.0 to 0.2, (although acid-leached mordenites can be lower than 0.2, e.g., 0.1) A 10 percent aqueous suspension of an acidic zeolite will have a pH less than 7, preferably less than 5.

These acidic zeolites are normally prepared from alkali metal-containing zeolites (which in 10 percent aqueous solution will have a pH greater than 7, and usually greater than 9) by ion-exchanging the alkali metal ions for H andlor polyvalent metal cations. I-Iydrocarbon-ion (or proton) exchange can be effected by exchange from aqueous or non-aqueous medium with mineral acids, such as dilute aqueous I-ICl, or by exchange with solutions of acids and polyvalent metal ions. Polyvalent metal exchange can be effected with solutions of salts of the metals, such as their nitrates. Alternatively the alkali metal-containing zeolite can be exchanged with a solution of an ammonium salt to form an ammonium zeolite which is converted to the acidic form by heating.

Prior to their use as catalysts the hydrous crystalline alumino-silicate zeolites are activated. In general, this activation takes place by controlled heating under vacuum or in a stream of a gas, such as air, hydrogen,

nitrogen, or oxygen, to remove water. In the case of ammonium-exchanged zeolites, not only water is removed but also the ammonium ion is decomposed to obtain a substantially anydrous, decationized or protonated zeolite. Such zeolites are similar, in catalysis, to these prepared by direct exchange with an aqueous acid.

When the hydrous ammonium zeolite also contains polyvalent metal ions, the resulting activated zeolite will be partially protonated or cation deficient. Such zeolites are not only highly acidic, but are more resistam to the detrimental effects of the activation procedure.

The heating rate and temperatures of such activation" will depend to a great extent on the type of zeolite, especially the Al/Si atomic ratio. and the type and percent of polyvalent cations and monovalent ions such has hdyrogen or ammonium ion. In any event the hydrated zeolite is first heated at a temperature sufficiently high to remove the bulk of the water from the pores of the zeolite. At atmospheric pressures this temperature is preferably from l25300C.

In the case of an ammonium-exchanged zeolite the temperature is then raised to a higher temperature than that used for water removal'and such temperature is maintained for a sufficient time to remove a substantial amount of the ammonium ion from the zeolite as Nl-l This removal also may involve decomposition of the ammonium ion by such reactions as oxidation of ammonia to nitrogen oxides or nitrogen and water.

At atmospheric pressure, with ammoniumexchanged zeolites which also contain appreciable quantities of exchanged polyvalent metal cations, this higher temperature is preferably 320-500C., but can be as high as 600 or 650C if care is taken to control the activation so as to retain at least 25 percent of the crystallinity of the zeolite.

Our copending application Ser. No. 716,190 compares alkylation with crystalline zeolite catalysts containing polyvalent metals and which were activated at various temperatures (e.g., 400, 500 and 600C.) and for varied periods of time. This data shows that these catalysts are all operative for alkylation. Analytical data is also presented which shows the reduction in OH groups (as residual H O) produced by such various activation procedures, particularly for temperatures in the range of 450l,292F. 7

With ammonium-exchanged zeolites which contain no polyvalent metal cations, it is important that the activation temperature be kept below about 400C since at higher temperatures the intensity of the X-ray diffraction peaks of the zeolite decreases greatly (due to a degradation of crystalline structure), and the resulting catalyst is less active for paraffin-olefin alkylation. In U.S. Pat. No. 3,130,007 a similar intensity measurement is used to determine the percent zeolite, and appears to relate to crystallinity of the zeolite.

If an ammoniumexchanged crystalline alkali metal zeolite is further exchanged with polyvalent metal cations, the resulting polyvalent metal-NH,+ exchanged zeolite retains a much greater proportion of its X-ray peak intensity after activation than does the base Nl-I,+-exchanged zeolite.

The present invention relates, for example, to crystalline zeolite Y containing at least one cation comprising cerium for every nine atoms of aluminium. When in acidic and substantially anhydrous form this zeolite has high alkylation activity when used as catalyst and retains a high degree of X-ray peak intensity on activation or regeneration. Preferred cerium containing cations are Ce, CeOI-I, CeOI-I", Ce(OI-I) and CeO.

As used herein the term zeolite Y is intended to mean the material defined in US. Pat. No. 3,130,007, which is marketed by the Union Carbide Corporation as Linde Y.

The cerium containing zeolites of the present invention may be prepared by ion exchange in a solution containing cerium ions (preferably dilute, e.g. 0. l-6wt percent hydrated cerium III nitrate and preferably having a pH in the range of 4-6. more preferred 4.5.10.5).

In general, the concentration of the exchange solution should be no greater than that of a saturated solution at ambient temperature (e.g., about 65F). Although, exchange at an elevated temperature below boiling (e.g., C) is preferred, a solution of greater concentration than saturated at ambient temperature can lead to occlusion of precipitated salt (due to cooling during the filtration step.)

Similarly, a pH above about 6.0 can lead to hydroxide precipitation and a pH below about 4.0 can lead to destruction of crystallinity.

A preferred process for preparing a substantially anhydrous acidic crystalline zeolite Y containing polyvalent metal cation (e.g., comprising cations of cerium) comprises:

a. ammonium ion exchange of crystalline sodium Y zeolite until the resulting ammonium-exchanged Y zeolite contains on an ignited basis, no more than 3 percent by weight sodium (more preferred, no more than about 10 percent of the exchange capacity of the zeolite should be satisfied by Na*);

b. further exchanging the ammonium-exchanged zeolite with a solution containing cations of a polyvalent metal (e.g., cerium ions), until the zeolite contains, on an ignited basis, a high polyvalent metal cation content (e.g., at least 7 percent by weight of cerium,) preferably, at least 40 percent (more preferred 6080 percent) of the exchange capacity should be satisfied by such cations.

c. heating the zeolite to a temperature in the range of about 125300C until there is substantially no further weight loss; and

d. subjecting the zeolite to a temperature in the range of (320700C, more preferred 320-500C) in the presence of a gas until substantially no further evolution of ammonia occurs.

For example, the ammonium exchanged zeolite Y is further exchanged with an aqueous solution of cerium nitrate (pH about 4.0-4.5).

ILLUSTRATIVE EXAMPLES The present invention may be further illustrated by the following specific examples. Examples I-Vl illustrate the preparation of acidic, or potentially acidic, solvated crystalline zeolites by aqueous cation exchange. Example VII illustrates the activation of the solvated zeolites by removing solvent from the zeolite.

The remaining examples, illustrate the use of such substantially anhydrous acidic crystalline aluminosilicate zeolites as alkylation catalysts. Of these, Examples VIII-XII show the effect of reaction temperature on the yield and product distribution. Examples X, XI and X11 show the unexpected, large increase in product yield effected by the use of various halide adjuvants.

Example XIII illustrates the effect of the gas used in catalyst activation on the paraffin yield, perweight of 8 olefin charged, obtained from the resulting catalyst.

Example XIV illustrates the correlation between alkylate yield and the ESR measurements of total spin count when aromatic hydrocarbons are adsorbed on the CeI-IY catalyst.

Example XV illustrates the effect that catalyst composition can have on yield and product distribution in alkylation.

In the Examples which report a catalyst analysis, such data can be used to calculate the coefficients in the previously referred to empirical zeolite formulae. Such coefficients for the formula a(I O):b(IIO):C(III O):d(IV O;Al O .eSiO are reported below for certain zeolites of the examples (along with certain necessary additional coefficients The above formula omits the content of non-metal cations (H ,NI-I in the zeolite. A more precise formula for an NaNI-l I-ICe Y zeolite is:

a(Na o)a2[(NH,) O]a3(l-I O):c(Ce O):Al O

:eSiO These coefficients are reported below:

Sample No.

a 112 113* c e E1 0.0876 0.1208 0.1087 0.6823 4.70 E5 0.0971 0.1161. 0.0898 0.6966 E7 0.1018 0.0213 0.1774 0.6966 E8 0.1066 0.0213 0.1585 0.7107 E9 0.0805 0.0213 0.1940 0.7035

' corresponds to l-l" derived from deficiency in ion-summation and represented as H,O." Runs E7. E8 and E9 showed a positive nitrogen content of less than 0.1 weight percent (the limit for the analytical method).

Note that in these zeolites the coefficient a is about 0.1, c is about 0.7, e is about 4.7 and the sum of a2+a3 is about 0.2, corresponding to about 0. l (I20):0.7(III2I3O)ZAI2O3:4.7SIOZ, for the less precise general formula. A more precise expression could be 0.3(I 2O):O.7(IlI2/3O)IA]2O3I4.7SIO2 where the a coefficient also includes a2 and a3 for the non-metal monovalent cations.

Another means of reporting zeolite composition (e.g., see U.S. Pat. No. 3,236,762) is to calculate the cation distribution, based on elemental analysis of the zeolite (and assuming that electronic balance is preserved by protons or 11*, which are, thus, calculated by difference).

The following table reports such cation distribution for certain zeolites of the examples (where M"" repre- Sems lssati s 9 p ly met l as C Example Analysis "As Is" Basis Cation Distribution No Na %N %M*" L01 Na NHJ' Ce IV 0.69 0.68 10.1 24.4 9.4 15.3 7.0 68.3 1V 0.23 0.8 10.3 24.7 3.2 18.0 9.4 69.6 V 1.69 9.6 25.l 22.9 13.2 639 V1 0.63 7.7 26.4 9.0 36.7 54.3 Vl 0.22 2.8 5.3 27.6 3.0 48.2" 48.8 V1 1.3 0.26 9.9 22.5 16.9 19.4 63.7

' "As Is" basis is. generally, for the dried zeolite ulter equilibration in u dessicutor ovcr u sodium chloride-water solution Calculated by difference since nitrogen unulysis uppcurs to be high. perhaps due to occluded ammonium stills).

For convenience, the cation distributions in the above table can be rounded off to whole numbers and reported in the following manner:

Example I This example describes the ammonium exchange of a crystalline. alkali metal alumino-silicate zeolite which can be heated to remove loosely bound water and to decompose the ammonium ion to produce a substantially anhydrous acidic crystalline alumino-silicate zeolite which can be used as a catalyst in our process. Preferably, before such decomposition or decationizing, such ammonium-exchanged zeolites are further exchanged with polyvalent metal cations, as is shown in Example III hereinafter.

A kilogram of a commercially available hydrated crystalline alumino-silicate zeolite, identified as sodium zeolite Y, was dried in air at 125C. for 18 hours, broken up into particles of 100 mesh or less, redried in air at 125C for 18 hrs., and suspended with stirring, in 1.7 liters of a 9.1 percent by weight aqueous solution of ammonium chloride at 80C. After 30 minutes the resulting ammonium-exchanged Y zeolite was separated from the liquid by filtration and recontacted at 80C. in a similar manner with a second 1.7 liter portion of fresh NI-l Cl solution. After six more such 30-minute exchange cycles, the filtered zeolite was washed with distilled water (pH 6.5) at 20C. until no chloride ion could be detected in the spent wash liquid with acidic silver nitrate reagent. The washed ammonium-exchanged zeolite was dried for about 18 hours in air at 125C., then ground to about 200 mesh and stored. The dried ammoniumexchanged zeolite produced by the above series of eight ammonium exchanges analyzed 1.34 percent Na and 4.6 percent N, and had a loss on ignition of 26.5 percent. After the first ammonium-exchange cycle, a similarly washed and dried portion of the zeolite analyzed 5.5 percent Na and 2.3 percent N, and had a loss on ignition of 25.6 percent.

The sodium Y zeolite before this ammonium exchange had a pore size sufficiently large to enable it to absorb benzene and analyzed 7.5 percent sodium and 8.86 percent aluminum, and had an Al/Si atomic ratio of 0.40. The sieve had a loss on ignition at 1,800F. of 23.8 percent. All ignition losses referred to hereinafter were run at 1,800F.

Example II This example illustrates the preparation of more highly ammonium-exchanged zeolites than that of Example I. Example I was repeated except that the sodium Y zeolite was subjected to eight additional hot NH ,Cl exchange cycles before it was washed chloride free. The washed, dried ammonium-exchanged zeolite,

resulting from this total of 16 ammonium-exchange cycles, contained 0.77 percent sodium and 4.14 percent nitrogen, and had 29.8 percent loss on ignition.

A similar exchange for a total of 32 cycles produced a washed, dried zeolite containing 0.21 percent Na and 4.64 percent N and having 28.7 percent loss on ignition.

Ammonium exchange of alkali metal zeolites can also be accomplished by suspending the zeolite in a vessel containing the exchange solution and maintaining a flow of fresh exchange solution into the vessel while withdrawing an equal volume of catalyst-free liquid from the vessel. Removal of catalyst-free liquid from the vessel can be effected by forcing the liquid with pressure or suction through a pleated microporous, woven stainless steel screen 10 micron filter. In such continuous flow processing, the flow rate is preferably regulated so as to maintain a relatively constant pH in the exchange vessel. Hydrochloric acid or nitric acid addition can also be used for pH control. With 10 percent ammonium chloride solutions it is preferred to maintain a pH of about 4.5 i 0.3 (at C.). Ammonium exchange can also be effected by percolating the exchange solution through a fixed bed of zeolite.

Example III This example illustrates the further exchange of an ammonium-exchanged zeolite with a solution containing polyvalent metal ions in order to produce a zeolite containing both polyvalent metal ions and ammonium ions. A portion of the dried, ammonium-exchanged zeolite of Example I was contacted, with stirring, for 30 minutes at 80C. with 1.7 parts by weight of a 1.3 percent solution of Ce(NO 61-1 0, then separated from the exchange solution by filtration and recontacted for 30 minutes at 80C. with 1.7 parts by weight of fresh cerium nitrate solution. After six more such exchange cycles (or a total of eight exchanges), the filtered Ceexchanged/ammonium-exchanged zeolite was washed with water until no nitrate ion could be detected in the spent liquor by diphenylamine reagent. The washed Ce-Nl-lf Y zeolite was dried for 18 hours at C., ground, redired for 18 hours at 125C., and stored in a moisture-tight container. The dried Ce -NH exchanged zeolite analyzed 6.18 percent Ce, 1.25 percent Na, and 1.43 percent N. It had a 25.6 percent weight loss on ignition.

Example IV This example illustrates the use of additional ceriumexchange cycles and a more highly ammoniumexchanged base zeolite in order to obtain zeolites with a greater cerium content and a lower sodium content than the zeolite of Example III. A portion of the washed, dried l6 cycle Nl-If-exchanged zeolite of Example II was contacted according to the procedure of Example III for a total of 16 Ce(NO exchange cycles, then similarly washed and dried. The resulting Ce -Nl-l -exchanged zeolite analyzed 10.1 percent Ce, 0.69 percent N, 0.68 percent Na, and had a loss on ignition of 24.4 percent.

A similar series of 16 cerium exchanges performed on the 32 cycle ammonium-exchanged zeolite of Example Il produced a washed, dried Ce -NH, exchanged zeolite which analyzed 0.23 percent Na, 10.3 percent Ce, 0.8 percent N, and had a loss on ignition of 24.7 percent.

Hereinafter, sometimes, a catalyst will be identified according to the number and type of such exchange cycles according to the code: number of ammonium exchange cycles/number of polyvalent metal exchange cycles. That is, the above zeolite prepared by 6 cerium exchange cycles of a 32 cycle ammonium is, by this code, a 32/ 16zeolite, (or, after activation, a 32/ 16 catalyst).

Example V This example illustrates the preparation of a Ceexchanged sodium Y zeolite. A portion of the commercial sodium Y zeolite of Example I was ground and exchanged for 16 exchange cycles with Ce(NO solution in a manner similar to the exchange of Example Ill, then washed and dried. The resulting Ce -exchanged Na Y zeolite contained 9.6 percent certium, 1.69 percent sodium, and had a loss on ignition of 25.1 percent.

The cerium exchanges of Examples III, IV and this example can be effected in a continuous manner, similar to that described in Example II for ammonium exchanges. Preferably the pH should be about 4.5. The particular polyvalent metal salt chosen and the pH of the exchange solution will determine whether the cationic exchange species is the metal or a hydroxylated complex ion of the metal. Other polyvalent metal ions, such as those referred to hereinafter, and in particular cations of the polyvalent rare earth metals and mixtures thereof, may be similarly exchanged with alkali metalcontaining and/or ammonium-containing crystalline zeolites. Especially preferred catalysts can be obtained from crystalline alumino-silicate zeolites which have been so exchanged with aqueous solutions of salts of gadolinium, such as Gd(NO or with mixtures of salts of Gd and Ce. In this specification the term rare earth metals includes lanthanum, that is, the term rare earth herein is used as a synonym for lanthanon." The lanthanons include La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb and Lu.

Example Vl This example illustrates the ammonium exchange of a Ce -exchanged sodium Y zeolite. A portion of a washed, dried cerium-exchanged zeolite prepared similar to that of Example V and containing 7.7 percent Ce, 0.63 percent Na and with 26.4 percent loss on ignition was exchanged with hot aqueous ammonium chloride, for a total of eight cycles, using the procedure of Example I. The washed, dried NH, -Ce -exchanged Y zeolite analyzed 0.22 percent Na, 2.8 N, 5.3 Ce and had a loss on ignition of 27.6 percent. Therefore, about 30 percent of the cerium was removed from the ceriumexchanged Na Y zeolite during the ammoniumexchange cycle.

An alkali metal zeolite which was exchanged by the reverse procedure, that is, eight ammonium exchanges followed by 16 cerium exchanges, contained 87 percent more cerium (it analyzed 9.9 percent Ce, 1.3 percent Na and 0.26 percent N, and had a loss on ignition of 22.5 percent).

Example Vll This example illustrates a preferred method of activation of hydrous crystalline alumino-silicate zeolites prior to their use as catalysts in our paraffin-olefin alkylation process. In general, hydrous crystalline zeolites are activated by controlled heating under vacuum or in a stream of a gas, such as air, hydrogen, nitrogen, helium or oxygen, to remove water. In the case of ammonium-exchanged zeolites, not only is loosely bound water removed but also the ammonium ion is decomposed to obtain a substantially anhydrous, decationized or protonated zeolite. Such zeolites are highly acidic and are similar catalytically to those prepared by direct exchange with an aqueous acid.

When the hydrous ammonium zeolite also contains polyvalent metal ions, the resulting activated zeolite will be partially protonated or cation deficient." Such zeolites are not only highly acidic, but are more resistant to the detrimental effects of the activation procedure.

The heating rate and temperatures of such activation will depend to a great extent on the type of zeolite, that is, the Al/Si atomic ratio, and the type and percent of polyvalent cations and monovalent ions such as hydrogen or ammonium ion. In any event the hydrated zeolite is first heated at a temperature sufficiently high to remove the bulk of the uncombined or uncomplexed water from the pores of the zeolite. At atmospheric pressures this temperature is preferably from l25300C., most preferably from l25240C.

In the case of an ammonium-exchanged zeolite the temperature is then raised to a higher temperature than that used for such Water removal and such temperature is maintained for a'sufficient time to remove a substantial amount of the ammonium ion from the zeolite as NI-l This removal may also involve decomposition of the ammonium ion by such reactions as oxidation of ammonia to nitrogen oxides or nitrogen and water.

At atmospheric pressure, with ammoniumexchanged zeolites which also contain appreciable quantities of exchanged polyvalent metal cations, this higher temperature is preferably 320500C.

With ammonium-exchanged zeolites which contain no polyvalent metal cations or have a low content of polyvalent cations, it is important that the activation temperature be kept below about 400C., since at higher temperatures the intensity of the X-ray diffraction peaks of the zeolite decreases greatly (due to a degradation of crystalline structure) and the resulting catalyst is less active for paraffin-olefin alkylation. In US. Pat. No. 3,130,007 a similar intensity measurement is used to determine the percent zeolite, and appears to relate tocrystallinity of the zeolite.

We have also found that, if an ammonium-exchanged crystalline alkali metal zeolite is further exchanged with polyvalent metal cations, the resulting polyvalent metal NI-Ii-exchanged zeolite retains a much greater proportion of its X-ray peak intensity after activation than does the base NHf-exchanged zeolite. Although small quantities of polyvalent cations will be of some benefit in this respect, for our catalysts it is preferable that the zeolite contain at least the following quantity of polyvalent metal cations (or a combination thereof of equivalent valence):

1. at least one tetravalent metal, metal oxide or metal hydroxide for every 16 atoms of aluminum in the alumino-silicate tetrahedra of the zeolite, or

2. at least one trivalent metal, metal oxide or metal hydroxide for every 12 atoms of aluminum in the alumino-silicate tetrahedra, or

3. at least one divalent metal, metal oxide or metal hydroxide for every 8 atoms of aluminum in the alumino-silicate tetrahedra.

In addition, for optimum activity, the polyvalent cation should be selected from classes 1, 2 and 3 above (and mixtures thereof) when the atomic ratio Al/Si of the aluminosilicate tetrahedra comprising the zeolite is greater than 0.65, or from classes 2 and 3 above (and mixtures thereof) when the atomic ratio Al/Si is from 0.65 to 0.35, or from class 3 above when the atomic ratio Al/Si is less than0.35. For example, the cation of our zeolite catalyst is preferably selected from the following:

l. at least one cation selected from the class consisting of V, Mo, W, Pa, U, VOl-l, Cr(OH) CrO, MnO, Mn(l-l) NbOl-l, MoOh, Mo- (Ol-Df, M00, RuOf, Ru(Ol-l) RuO, Ru- (OH) SbOl-l, OW, W(OH) WOH, Re- (OH) Re(O1-l) ReO, Os(Ol-l)., 050 00s, Os(Ol-l) IrO, MOI-1);, Biol-1 PaOl-l, U0, U(OH) and UOH, when Al/Si is from 1.0 to 0.65,

Thomsonite, levynite, and the Type X zeolite of U.S. Pat. No. 2,822,244 are crystalline zeolites having an Al/Si atomic ratio greater than 0.65. Analcite, chabazite, phillipsite, and the Type Y zeolite of U.S. Pat. No. 3,130,007 have Al/Si ratios between 0.65 and 0.35. l-leulandite and the Type L zeolite of U.S. Pat. No. 3,013,984 have Al/Si ratios less than 0.35. Mordenite has an Al/Si ratio in the range of 0.2 and some mordenites have been reported to have an Al/Si ratio appreciably less than 0.2 (e.g., 0.13). Such low Al content mordenites, when exchanged and activated by the procedures taught herein, have some catalytic activity in our process but are not among our preferred catalysts.

As catalysts in our process we further prefer substantially anhydrous protonated alumino-silicates which are capable of adsorbing benzene, wherein the ratio Al/Si in the tetrahedra is from 0.65 to 0.35 and which contain at least one rare earth metal cation for every 9 aluminum atoms in the tetrahedra since such catalysts have high alkylation activity and retain a high degree of X-ray peak intensity on activation or regeneration.

For example, in illustration of our preferred method of activation of a preferred species of hydrous zeolite, the l6-cyc1e Ce -exchanged/l6-cycle NIL-exchanged zeolite of Example IV was heated at 230C. in a rotating kiln in a stream of flowing air for about 1 hour toremove water. No loss of ammonium ions was detected during this heating period. The temperature of the kiln was then raised at the rate of about 10C. per minute to a temperature of 400C. During this heating, ammonia could be detected, by MnSO,,-AgNO reagent, in the exhaust gases from the kiln. The kiln was maintained at 400C. for 2 hours, at which point no ammonia could be detected in the exhaust gases. The heat was then removed from the kiln and the kiln was cooled rapidly in a flowing stream of dry air. The activated catalyst was maintained overnight in a slowly flowing stream of dry air. The resulting, substantially anhydrous, protonated crystalline alumino-silicate had a loss on ignition of 3.7 percent.

Summation of the intensity of the significant X-ray diffraction peaks of the hydrous zeolite before activation and of an activated sample showed no decrease in intensity for the activated zeolite. In contrast, a similarly activated portion of the base 16-cycle ammoniumexchanged zeolite showed an intensity decrease of 64 percent.

To illustrate the stabilizing effect of even small quantities of polyvalent metal ions, a sample of the base 16- cycle ammonium-exchanged zeolite was submitted to a 16-cycle Ce" exchange using l/lO the usual cerium salt concentration to produce a dried, washed zeolite which analyzed 1.23 percent Ce (ignited basis). After activation according to the above procedure, the activated zeolite showed an intensity decrease of 47.4 percent.

The bulk density in g/ml of the dry (at C.) hydrated zeolite is about 0.71 for sodium Y zeolite, 0.78 for highly ammonium-exchanged sodium Y zeolite (NI-LY), 0.90 for highly cerium-exchanged NH Y (CeNl-LY) and 0.89 for highly Gd-exchanged Nl-l Y (GdNl-LY). If one assumes no significant volume change in activation, the calculated bulk density of the corresponding activated or substantially anhydrous zeolite would be in the range of 0.6 g/ml for the NaY and 0.75 g/ml for the Cel-lY.

Quantitative studies of the activation of equilibrated" highly ammonium-exchanged sodium Y zeolite (hereinafter, sometimes Nl-LY) and cerium exchanged, Nl-l Y (hereinafter, sometimes CeNH Y) have shown that, in our preferred catalysts, even after our optimum activation, water can be evolved from the catalyst upon ignition at 1,800F. This water is called hereinafter sometimes, bound, or combined or complexed water to distinguish it from that water which is readily evolved from the .exchanged zeolite below 300C. Equilibrated zeolite is a zeolite which has been exposed to air of about 50 percent relative humidity, at about 68C. for about 12 hours.

We have further established that our preferred substantially anhydrous, acidic crystalline zeolite catalyst, containing polyvalent metal ions and, more preferably, having some degree of protonation, sometimes termed cation deficiency, will evolve substantially no bound water when heated for about one hour at 300C. but when ignited at l,8,00F. will evolve about A to 2 mole of water for each atom of exchanged polyvalent metal. In particular, in our novel, activiated, ceriumcontaining catalysts, for each atom of cerium in the catalyst, 0.8 to 1.2 molecules of water will be evolved upon ignition at 1,800F.

We have concluded that in the catalyst this water is present, mainly, in the form Ce(Ol-1) To understand the basis for this finding, one must first consider the behavior on activation of the hydrated NaY and NH Y zeolites. Behavior of Nl-LY catalyst during activation at temperatures from 150 to 1,292F. (65 to 700C.) and for times up to 4 hours, as is summarized in Table 1 Two series of experiments were performed. Experiment A being at different times at constant temperature and Experiment B being at different temperatures at constant time. Total water (that is, sorbed and combined) appeared to be retained by this catalyst more firmly than ammonia.

Table 1 shows that about two-thirds of the total water present on dried Nl-LY zeolite had been removed after 1 hour at 450F. This water removal is an endothermic reaction and probably represents loosely held water that is in molecular form when sorbed. Data from DTA-EGA measurements agree with this observation.

Water removable only at 750F. and higher temperatures is more firmly bound and is chemically combined in a form other than molecular H O. Ammonia, which is largely in the form of NH, ions, was removed more readily than the water which remains after one hour at 450F. Furthermore, ammonia removal releases protons (Nl-l NH H*). When an activated Nl-LY zeolite is ignited at 1,800F., OH groups are destroyed and B is evolved in an amount equivalent to one molecule of H 0 for every two OH groups.

Uytterhoeven, Christner and Hall, J. PHYS. CHEM., 69, 21 17-26 (1965), have proposed the following stoichiometry to account for protonation and dehydroxylaand Experiment A-activation for zero time at each temperature H,,O Difference (g. mole) Temp., F. (Experimental-Calculatedl Experiment B-activntion at 750F.

H O Difference (g. mole) Time, min. (Experimental-Calculated) It is interesting to note that in most instances the excess H O in the preceding table is about numerically equivalent to the residual sodium value of about 0.044 g. ion all on the basis of 100 g. anhydrous base. Carter, Lucchesi and Yates, .l. PHYS. CHEM., 68, 1385-1391 (1964), described IR bands on NaX zeolite at 3,400 and 1,655 cm" which persisted up to 450C. (842F.) and which they concluded were due to residual hydrogenbonded polymeric water. It is probable that the H 0 measured over and above that produced from intact and deaminated NH, sites is this hydrogen-bonded water structurally related to residual Na species in the lattice.

In fact, the NaY zeolite itself may contain more than one kind of H 0. For example, if it is assumed that the 0.414 g. ion- Na had one mole H O associated and that this represents strongly bound H O then the H 0 equivalent is 7.46 wt. percent H O. This firmly bound H O would represent 31 percent of the total 24.32 wt. percent 11 0 found (Table l With Nl-l Y, about 33 percent of the B 0 was firmly bound enough to remain after one hour at 450F.

Activation studies of two ammonium-, ceriumexchanged catalysts were made in a manner similar to those for Nl-LY. v

Cerous nitrate exchange of NH Y catalysts replaced most of the NH, ions with cerium but removed only 20-25 percent of the small residual sodium (Table 2 The Ce -exchanged product, therefore, contained residues of NH, and Na*. In contrast to NH Y catalyst, the subsequently Ce -exchanged material was able to lose NH, during activation down to a level of 0.01 mole/100 g. or less at 750F. The NH Y had required temperatures above 750F. to accomplish this degree of removal.

The sum of chemical equivalents for Na*, Nl-l, and Ce after exchange was always noticeably less than the 0.414 g. ion Na 100 g. anhydrous base found with the original NaY zeolite. One explanation for this cation deficiency of the exchanged catalyst is that some protons are structurally incorporated during exchange but not directly measured by analysis. Chemically this incorporation is possible because the pH of the cerous nitrate solution was about 4.5, and favored cerous salt hydrolysis.

An increase in SiOH groups and a growing cation deficiency was observed as the catalyst became progressively deaminated during activation. However, the SiOH groups and intact NH, ions were not enough to account for all of the H measured by ignition loss at 1,800F. Total H O measured was 0.16 to 0.10 mole/ 100 g. anhydrous base, but SiOH and NH, could not have produced more than 0.05 mole H O on ignitron.

The NH Y study showed'that residual sodium 'ions were complexed at a H O/Na ratio of about 1. Continuation of this behavior in the Ce -exchanged catalyst could at most produce 0.04 mole H O on ignition. Therefore, the water not derivable from SiOH, NH,

and Na* amounted to nearly half the measured H O.

Another source was obviously contributing to the total.

Calculation of (H O)/Ce ratios, are shown for two 750F. activations in Table 3. Calculation of H 0 measured at 1,800F. does not imply the existence of associated molecular water but is equally capable of interpretation as ce(OH) species according to the equation:

This correspondence of measured water to the amount needed for Ce(Ol-l)"" formation indicates that substantially all of the cerium in Type Y zeolite activated at 750F. (400C.) is in this form or in an equivalent combination of such forms as Ce, Ce(OH)" Ce- (OH) Ce +4 and Ce(OH) A 750F. activation with a sample of the same hydrated CeNH,Y zeolite in another experiment revealed an H O/Ce ratio of 1.041 (Table 4 Continuing this experiment at a series of temperatures up to 1,292F. (700C.) showed a steady decline of the ratio to 0.370 with increasing temperature. Heating for up to 4 hr. at 750F. did not lower the H O/Ce (or Ce(OH) total Ce) ratio effectively below 1. NH removal occurred during that time, and, thus, SiOH increased accordingly as evidenced by the growing cation deficiency. Ce- (OH) however, was far more stable, and that behavior in itself is more indicative of Ce(OH) than of Ce(H O) Only by increasing temperature above 750F. could the fraction of total Ce in the Ce(OH) state be reduced.

Isoparaffin-olefin alkylations with NH Ceexchanged Type Y gave maximum alkylate yields and selectivity when the catalyst had been activated at about 750F. rather than at lower or higher temperatures. Possibly, maximal Ce(OH) establishes the sites needed for isoparaffin-olefin alkylation. Also, Ce exchanged Type Y catalysts have been far more stable toward temperatures above 400C. than NH,Y, as measured by X-ray diffraction. When Ce(OH) sites become dehydroxylated, Ce and Al Si species can re-formfirit lie Biifefiifid, dehydroxylation of A1 and Si species. Very possibly the entire complex is required to achieve the carbonium ion-olefin combinations accompanied by good hydride transfer which are vital for a highly paraffinic alkylate. Structural considerations further suggest that only a portion of these complexes may be effective for alkylation, even though enough H O for total Ce(Ol-l.) formation is a necessary ingredient of catalyst composition.

As is shown hereinafter, catalytic activity for paraffin-olefin alkylation is related to cerium content. ESR total spin counts of these catalysts with aromatics (such as benzene, perylene, anthracene, etc.) sorbed on them revealed a dependence of electron withdrawal ability upon cerium content. Calculations reveal about 5 percent of the cerium ions to be on the external catalyst surface and the data indicated a 1:1 numerical correspondence between these ceriums and the total spin count.

As is illustrated hereinafter in Example XIV, there is a nearly linear relation between the total ESR spin count of adsorbed aromatics on our cerium catalyst (when activated at temperatures below about 450C.) and the alkylate yield under a given set of reaction conditions. In general the more preferred ceriumcontaining catalysts have total ESR spin counts above 3 X l0 /g. with anthracene. Thus, there is a correlation between alkylate yield with its essential dependence upon hydride transfer and the electron withdrawal from anthracene by our catalyst.

Example Vlll This example illustrates the use of substantially anhydrous acidic crystalline alumino-silicate zeolite as a paraffin-olefin alkylation catalyst. The activated l6- cycle Ce 3/ l6-cycle NHf-exchanged zeolite of Example VII was charged in amount of 23.3 g. into a oneliter, stirred autoclave containing a four-member baffle to diminish vortex formation. Then 444 milliliters of liquid isobutane was added. The stirring rate (of a sixmember, flat-blade turbine) was adjusted such that substantially all of the zeolite was suspended in the liquid isobutane (about 550 rpm). The temperature in the reactor was raised to 80C. using sufficient nitrogen to produce a total pressure of 250 p.s.i.g. Under these conditions nearly all of the hydrocarbon is in the liquid phase. Then a liquid mixture of one part by volume of butene-2 and five volumes of isobutane was charged from a Jergu'son gauge via a needle valve and dip tube into the isobutane-catalyst slurry (and near the bottom of the reactor) at the rate of l milliliter of mixture per minute for a period of 220 minutes. Nearly all of the hydrocarbon was maintained in liquid phase. At the end of this time the reaction was stopped by cooling the reactor to 17C., then separating the reaction mixture from the catalyst by first removing the normally gaseous hydrocarbons at room temperature and atmospheric pressure, and then separating the liquid product from the catalyst by filtration. The used catalyst analyzed 0.9 percent coke (nonvolatile residue). Some propane and n-butane but no methane, ethane, ethylene or propylene were found in the normally gaseous hydrocarbons. The C; paraffin yield of the reaction mixture, based on the weight of olefin charged, was 7 l .4 percent and the C unsaturate yield was 0.24 percent on the same basis. Hereinafter all yield data are reported as based on the weight of olefin charged.

Example IX When the reaction of Example VIII was repeated except that the temperature was 120C. and the pressure 475 p.s.i.g., the C paraffin yield was 129.4 percent and the unsaturated C hydrocarbon yield was 4.3 percent.

Table 5 further characterizes the C; product obtained in the reactions of Examples VIII AND IX.

Example X This example illustrates the unexpectedly large increase in degree of conversion of olefin reactant to saturated C hydrocarbon product when a small amount of a halide adjuvant is present in the reaction mixture. The reaction of Example VI" was repeated at 60C. except that the catalyst used was the 32/ 16 zeolite of Example IV which had been prepared by 32 NH,*- exchange cycles followed by 16 Ce -exchange cycles. The catalyst was activated by the procedure of Example VII. Without halide addition at 60C., the' yield of C; paraffins was 90 percent and the yield of C unsaturates was I 1.5percent. On a mole basis this amounted to 0.44 mole of C paraffins per mole of C olefin charged. In contrast, when 2.4 X mole of tertiary butyl chloride (hereinafter, sometimes TBC) was added to the reactor for each mole of initial isobutane, the yield of Cfparaffins was lpercent and C; unsaturates 6percent. The TMP/DMH, ratio was 6.6. The used catalyst had no measurable coke content.

Example XI With the same proportion of t-butyl chloride the reaction of Example X was repeated at 40C. (125 p.s.i.g.) and at C. (125 p.s.i.g.). At 25C. only l2percent of C paraffins was produced, and 0.49percent of C; unsaturates. at C. l20percent of C; paraffins was produced and 6.5percent of C unsaturates. The TMP/DMH, ratio was 4.10 at 25C. and 7.86 at 40C.

Example XII When Example X was repeated at 120C. (484 p.s.i.g.) without halide addition, percent of C paraffins and 1.1percent of C; unsaturates were produced. The TMP/DMI-I, ratio was 3.16.

Of commercial importance is the finding that, by practice of our invention, we cannot only obtain good yields of alkylate which has a high TMP/DMI-I, ratio and is high in trimethylpentanes but that in these trimethylpentanes there is a low proportion of the less desirable 2,2,4-trimethylpentane (regarding this undesirability, see US. Pat. No. 2,646,453).

Example XIII Table 5 reports the products obtained from similar runs at C. using the activated catalyst of Example VIII with t-butyl chloride, n-propyl chloride or n-butyl chloride as adjuvants (at a level of 2.4 X 10 mole of adjuvant per mole of initial isobutane).

It is interesting to note that 60C. with the 16/ 16 catalyst produced no more than half as much alkylate as 80C. with this catalyst. The 32/16 catalyst was not so responsive to temperature changes above 40C. Again, as temperature decreased from 80 to 60C., a shift toward a heavier product occurred (Cf), but the 2,2,4- TMP content was desirably low. When this isomer decreased, the largest gain was in 2,3,3-TMP, as it had been with the 32/ 16 catalyst.

Temperature is a useful device in elucidating catalyst differences. When a catalyst exchanged only with NH, (32/0 was tested at C. without TBC promoter, it was less active than a 16/16 catalyst (Table 8). The C5 paraffin yields were 109.5percent, based on olefin charge, with 32/0 and 129.4percent with 16/16.

Evaluating an NI-If-exchanged catalyst (16/0) with TBC relative to 16/16 at 80C. revealed a more dramatic difference in alkylate yield and product distribution.

The 16/0 catalyst produced too little C paraffin and too much CJ and C These factors could also be used to understand the importance of a polyvalent metal, such as cerium, on the catalyst. But testing catalysts at milder conditions is even more effective in uncovering differences between them, as shown by the data from 32/0, 16/16, and 16/0. Therefore, low operating temperatures can be used as a research tool in distinguishing among alkylation catalysts that appear to be more similar at relatively high temperatures.

Example XIII Table 5 reports the products obtained from similar runs at 80C. using the activated catalyst of Example VIII with t-butyl chloride, n-propyl chloride or n-butyl chloride as adjuvants (at a level of 2.4 X 10" mole of adjuvant per mole of initial isobutane).

Table 9 reports the products obtained from similar runs (but with more intimate premixing of the feed olefin and feed paraffin) using CCl. TBC and various other adjuvants and using either continuous or pulsed" addition of the adjuvant to the reaction mixture. In this table, the amount of adjuvant is reported as millimoles per mole of feed olefin charged (m.mole/m. 0C).

In run 606 of Table 9, the catalyst was preconditioned by contact with a solution of perylene in CCh. The perylene was quantitatively adsorbed by the catalyst along with some CCl,. The catalyst developed a dark, intense, blue color upon contact with the perylene solution. Removal of residual CCl, by vacuumpumping at ambient temperature caused the catalyst color to turn to black. This black catalyst was the catalyst used in run 606.

1n run 600, the catalyst was preconditioned with carbon tetrachloride as a control experiment for 606. The catalyst developed an intense red color on contact with the CC],. Upon vacuum pumping, the red color disappeared. It is this pumped catalyst which was used in run 600. g

Potential catalyst adjuvants are those halides, both organic and inorganic (e.g., AlBr 8P HBCl AsCl which are capable, under the reaction conditions, of

sufficient polarization to promote carbonium ion reactions or to have carboniogenic properties. For precise control of the reaction product distribution (or alkylate quality). and to prolong catalyst life, we prefer to avoid adjuvants which contain atoms other than hydrogen, carbon, bromine, fluorine and chlorine (although as seen in run 632, oxygen, as in the form of alcoholic OH groups, can be present in reaction mixture. Water, C,

' to C saturated alcohols (e.g., tertiary butyl alcohol,

cyclohexanol) or mixtures thereof can be used, per se, as adjuvants or in combination with halides. To avoid accumulation of large organic molecules at the catalyst surface, we prefer to avoid those organic halides wherein the organic radical has a critical diameter greater than about 9A, such as the chlorinated naphthenic waxes. Note, however, in Table 9, that perylene presorbed on the catalyst from CC], solution did not act as a poison but allowed about 10 relative percent more C; paraffin yield than a control experiment with carbon tetrachloride alone. This carbon tetrachloride contr c p rirnent itse f prod dabst e n. 10 ative percent increase in C paraffin yield over a similar experiment with tertiary butyl chloride and without CCl4. In contrast, Nl-l presorbed on the catalyst acted as a poison, even when TBC was added continuously to the reactor.

Our preferred halide adjuvants, when present in solu-' tion in the reaction mixture at a level of from 1 X 10 to l X 10 mole per mole of C -C isoparaffin reactant, are HF, HCl, Hbr and the saturated halohydrocarbons containing at least one atom per molecule of bromine, chlorine or fluorine. Mixtures of these substances can also be used as adjuvants. Of these adjuvants, we prefer carbon tetrachloride and the aliphatic saturated monochlorides having no more than six carbon atoms. When the isoparaffin reactant is predominantly isobutane,we prefer to use, as halide adjuvants, the aliphatic saturated monochlorides having three or four carbon atoms.

The adjuvant can also be added to the catalyst after Temperature 01' Run the final washing, in the exchange procedure but, more preferably, is added to catalyst after activation, as by passing gaseous HCl through the catalyst at the final stage of activation (or while cooling catalyst after activation). It can be important, especially in our continuous process, to control the amount of adjuvant present in the reactor vapor space. 1

Although the previous examples are illustrative of practice of our invention, the yields of many of these examples based on the weight of olefin charged, can be improved upon since it is probable that some of the olefin feed was not consumed in the reaction, but was lost because of slight leakages from the reactor system. For example, T561; 20 reports two runs, at 80C., 250 p.s.i.g. with a catalyst similar to that of Example V111, which were identical except that Run A utilized the same reactor system as in the previous examples and Run B utilized the same system but greater care was used to prevent loss of feed olefin from the system. It can be seen that the yield in Run B was 12 relative percent greater than Run A.

The calculated F-l clear octane number of the alkylate of Run B (excluding materialsboiling higher than 2,2,4-trimethylhexane) was 98.0. This high octane number, in combination with the reported yield, is one indication of the commercial promise of our invention. Note that a similar calculation shows the novel alkylate of Example XIX (see Table 20) to have a 99.9 octane number.

dration, for example, at about 230C, which removes virtually all of the adsorbed water but probably does not affect hydroxyls or other waterforming entities more firmly incorporated into the structure. Third is the final activation stage, which is characterized by NH, decomposition and a relatively small removal of water. The activated catalyst, however, contains a definite and reproducible amount of water.

Early in the solid alkylation catalyst research program it had been observed that 400C. appeared to be a preferred temperature for catalyst activation in air. That observation has been verified with current techniques and more highly exchanged catalysts. The following yields are illustrative:

Catalyst Base Air Activation No. Paraffins Unsaturates SZNHJ, 16Ce" Y 325C. 842* 29.4 0.99

do. 400C. 782 119.0 5.85" do. 500C. 844* 113.2 1.83 IGNHJ, IGCe Y 400C. 868" 125.8 0.24 do. 400C. 880" 133.8 0.36 do. 500C 860" 107.8 1.96

Catalyst Compositions Qwt. ignited basis) Run No.

wt. cerium wt. sodium I Operating Conditions: C., 200 psig., 220 min., i-CJC.-ene 14.9

" Use of less preferred charge stock preparative technique for this run should ,not have affected C,

'"Operating Conditions: C.. 250 psig.. 250 n-rin., i-C IC -ene 14.9 Min.

min.

parat'fin yield but probably increased the unsaturate yield. I!

With the 32NH l6Ce Y-catalyst, a 5.8percent loss of C? paraffin yield was obtained after activation at 500C. relative to 400C. With the l6Nl-l l6Ce Y-catalyst, a 22.0 percent mean loss of C; paraffin yield was obtained by activation at 500C. instead of 400C. The poor result following 325C. activation may be a result of incompletely developed acidity in the solid or of residual ammonium, even though a negative test for ammonia evolution had been observed at the end of this activation. DTA and EGA experiments have shown that ammonium decomposition occurs at 300320C. with NH.,Y zeolite.

' To some extent the bdifiawzimsran activfiim at higher than optimum temperature can be re-introduced to the catalyst. A hydrated CeNH Y zeolite was activated by the progedure of Example VII, the final heating stage being at 400C. The resulting activated catalyst was contacted with an isobutane-butene-2 feed to produce a 141.5 percent yield of C paraffin.

A similar alkylation with a similar catalyst which ha d been activated at 600C. in the final step produced only 128.5 percent of C? paraffin.

Example XIV This example illustrates the correlation between alkylate yield and Electron Spin Resonance (ESR) measurements of total spin count when aromatic hydrocarbons are adsorbed on the CeHY zeolite catalyst.

Several kinds 0f aromatic hydrocarbonsY benzene, p-xylene, naphthene, anthracene, ,perylene, etc.) were adsorbed upon CeHY catalysts prepared by varied numbers of Ce and NH, exchange cycles and with various types of activation (e.g., temperature, type of gas). The total ESR spin count of the adsorbed hydrocarbon was then measured. The sorption of the aromatics corresponded to the order of decreasing ionization potential (benzene being first). Catalysts with a higher degree of exchange produced larger spin counts with any particular aromatic. When C paraffin yields obtained with similar catalysts were plotted versus the spin count with a particular aromatic on each catalyst, a good correlation was achieved.

The mostsaisfsaary eis'riaaribasaaeffirpauhas' having inonization potentials equal to or larger than that of naphthalene(about 8 ev.). Spin counts of compound with lower ionization potential changed less than one order of magnitude while relatively large differences in 'alkylate yield were being observed. These correlations imply a relationship between radigenic nature of a catalyst and its performance in an alkylation reaction (which is highly dependent upon hydride transfer).

A far more exact relation between alkylate yield and anthracene spin count was realized when a series of catalysts of increasing cerium but constant sodium content was used. Anthracene spin count increased less after a (Ce /NH equivalent ratio of about 2.5 had been reached.

Note, for example, a nearly liiieii'reiaiidn between alkylate yield and anthracene spintcount can be seenby plotting the data below:

Sorbed Wt. Cf Spin Count Note: Reactions at C.. Example Vlll conditions with improved feed premlxing". isobutane-butene-Z feed. Sodium in catalyst 11 to 137: of cation capacity of zeolite.

Poor hydride transfer, as represented by C unsaturate formation, was intensified at low (Co /N11 equivalent ratio. Other aspects of product quality -low C high C and high TM? in the C,,also improved when this composition ratio increased.

9 7 These data offer excellent supp oi t for the importance of the cerium in Cel-lY catalyst for alkylation and strongly imply a relation beween hydride transferfacility of a catalyst and its electron withdrawal ability.

In our process the preferred means residence time is in the range of 0.05 0.5 hour, more preferably 0.1 to 0.4 hour.

An illustration of the calculation of mean residence time, for the first 60 minutes in the reaction illustrated by FIGS. 1 and 2 in application Ser. No. 716,190, follows:

(444 m1. i butarie)(0.5543) 246. 11 'gfisabutane for entire time 23.3 g. of catalyst Change 1 vol. butene-2 (density 0.5988 g./ml.)

5 vol. isobutane (density 0.5543 g./ml.)

2.7715 +0.5988 3.3703 D* density of hydrocarbon mixture 0.5617 For 60 min.

(1 hour) (23.3 grams catalyst) (60 min.) (1 ml./min.) (0.5617 g./ml.)

2 w) 0.08861 hI./( g t l st Example XV This example illustrates the effect that catalyst composition has on the yield of C; reaction product and on the product distribution, in particular with regard to the proportion of C paraffms and the distribution of these C paraffins into trimethylpentanes and dimethylhexanes.

The process of Example Vlll was repeated except that the reaction temperature was C. (which was close to the critical temperature of the reaction mixture), the reaction pressure was 500 p.s.i.g., and the reaction time was 3.67 hours. Separate runs were made with equal weights (activated basis) of zeolites of varied Na, H and polyvalent metal contents, which were prepared similarly to the catalysts of Examples I1, 111, IV. and V.

Runs were also made, at 80C., 250 p.s.i.g., and 2.4 X moles t-butyl chloride per mole of initial ibutane, with catalysts prepared from the following: the 1.72 percent (ignited) Ce zeolite of Example VII; a 16- cycle ammonium-exchanged NaY zeolite which was further exchanged with 16 cycles of a 13.3 g./l. aqueous solution of La(NO .6H O; a 16-cyc1e ammoniumexchanged NaY zeolite which was further exchanged with 16 cycles of a 13.3 g./l.'aqueous solution of hydrated mixed rare earth nitrates (approximate salt analysis, 48 percent Ce- O 24 percent La O 17 percent Nd O 5 percent Pr O 3 percent Sm O 2 percent Gd O and, a l6-cycle ammonium-exchanged NaY zeolite which was further exchanged with 16 cycles of aqueous Ce(NO 6H O (as in Example 1V).

All of these catalysts were activated by the procedure of Example V11.

The yields of the C paraffin and C unsaturates, based on the weight percent of olefin charged, the C; paraffin distributin and the C paraffin distribution of the products are shown in Table 11.

The yields and product distributions shown in Table 1 1 indicate that, in substantially anhydrous acidic crystalline alumino-silicate zeolites which have been prepared by ammonium exchange of sodium zeolites with ammonium ions and polyvalent metal ions, the catalytic activity and selectivity in paraffinolefin alkylation are dependent upon the amount and type of exchanged polyvalent metal and the degree of protonation or cationic deficiency (which is related to the nitrogen content'before activation). Therefore, when other reaction variables are fixed, an appropriate selection of the catalyst can be used to vary the yield and product distribution in our process.

Table 12 and Table 13 illustrate the effect on the ultimate catalyst of the type of salt used in the exchange solution.

lt' is evident from Table 13 that the yield differences are not determined only by the total amount of rare earth metal present. Therefore, it appears that different cations and their accompanying anions can have pronounced effects on catalyst performance. Other desirable catalysts can be prepared by exchanging NH Y zeolite with salts of Gd, Dy" and Sm.

One precaution to be taken with data from Table 13 concerns the apparent gain in selectivity for C paraffins with the La(NO and CeCl catalysts. in fact, this gain is more in line with the selectivity gain which is typical when our process is operated at a relatively low degree of reactant conversion or product yield. In other words, if the Ce(NO catalyst had been used to produce only 68 to 73 percent C paraffin yield (the range for La(NO and CeCl the molar C paraffin content of the C paraffins would have increased to about 80 percent instead of remaining at the 69.0 percent actually observed at 132.0 percent C paraffin ield. y As shown by these data, the anion in the exchange solution exerts an influence on catalyst peformance. The effect is related to the condition of metal cations in aqueous solution as a function of anion, cation concentration, pH and temperature. An effect such as the following is the probable cause:

Other cations which can affect the catalyst are the v alkali metals, such as lithium, sodium, potassium and cesium. As shown in Table 14, at comparable sodium levels, C paraffin yield progressed from 26 to 132 wt. percent olefin charge for an increase of cerium from 2.0 to 13.5 percent. Even at 8.3 percent cerium, the C; paraffin was only 62.7 percent on the same basis. The probability that the 1.68 percent sodium content did not have the principal deleterious effect upon this 62.7 percent yield is supported by the 118.9 percent yield for a catalyst containing 2.8 percent sodium but 13.0 percent cerium and by the 115.4 percent yield for another catalyst with a 1.68 percent sodium and a 12.8 percent cerium content.

Some gain in C5 paraffin yield (1 15.4 to 132.0) can be inferred for a reduction in sodium content from 1.68 to 0.76 percent.

Selectivity effects of cerium are illustrated by the relatively high C unsaturate production with catalysts containing less than about 12 percent cerium. Trimethylpentane/dimethylhexane (TMP/DMH ratios were also comparatively low for those catalysts, and relatively undesirable C paraffins constituted as much as 27.2 mole percent of the total C; paraffins for the lowest cerium catalyst. These data show that with less than about 12 percent cerium, alkylate will be not only lower in yield but also poorer in quality.

A series of NH,*-, Ce -exchanged catalysts having very similar sodium levels clarified the essential role of cerium in producing favorable yields of high quality a1- kylate.

When cerium replaced ammonium on a Type Y zeolite at constant sodium level, the following effects were observed:

1. Appreciable gains were realized in C paraffin yield, in relative proportion of C paraffins and in selectivity for trimethylpentanes (TMP/DMH, ratio).

2. Simultaneously, desirable decreases were found in C unsaturates and in the relative proportion of C paraffins.

3. The only undesirable trend was an increase in the relative amount of 2,2,4-TMP up to 26.4 mole percent of the total TMP. However, typical sulfuric acid alkylates have 2,2,4-TMP contents above 40 percent. This isomer has the lowest F-l octane number of all the TMP.

4. The largest gains in yield and selectivities occurred at values of (Ce /NH equivalent ratio below about 2.5. Higher ratios are desirable, but corresponding product improvements become smaller.

These catalysts were prepared from the same common lot of NHf-exchanged Type Y zeolite. The following analytical data establish that Ce was exchanging for NH, and that no net loss of Na" occurred from the NHf-exchanged zeolite:

Catalyst Analysis (g. equivalent/ g. anhydrous -Continued Catalyst Analysis (g. equivalent/100 g. anhydrous No. residue) Na NH, Ce Z FXl-l-4 0.047 0.049 0.299 0.395

" Average of 3 analyses The original zeolite had a sodium content of 0.426 equiv./ 100 g. anhydrous residue after correction for 1,800F. ignition loss. Residual sodium content was thus 11-13 percent of the original.

Another interesting but undecided aspect of these catalysts is their growing cation deficiency as cerium exchange increases. A deficiency is said to occur when the sum of residual sodium, ammonium and rare earth does not equal the positive charged initial sodium. The presence of protonsbound or solvatedcan account for the apparent deficiency.

As has been shown in Examples I to VII, we prefer to prepare the substantially anhydrous acidic aluminosilicate zeolites by controlled activation of zeolites which are prepared from crystalline sodium zeolites by first exchanging the bulk of the sodium with ammonium ions and then exchanging the resulting zeolite, which is low in sodium and high in ammonium ions, with solutions of polyvalent metal cations. When the base zeolite is sodium Y, the ammonium, exchanged zeolite should contain, on an ignited basis, less than 3 percent Na and preferably less than 1.0 percent Na.

In our ammonium exchange we also prefer that the sodium content of the exchange solution be kept as low as is practicable. One means of removing sodium ions from ammonium salt solutions is by a separate cation exchange of the solution with a bed of ammoniumcontaining ion-exchange resins or non-crystalline ammonium zeolites. In this sodium-ion removal step, which is particularly advantageous in continuous ammonium exchange (as in the procedures of Example II), the sodium ion in the ammonium-ion exchange solution changes with the ammonium ion in the resin and the resulting ammonium-rich solution is recycled to the vessel containing the crystalline zeolite for additional exchange with the sodium in the zeolite. The ionexchange resin bed (or noncrystalline zeolite bed) can be regenerated by contacting the ammonium-sodium equilibrium resin with an ammonium-rich stripping stream. The sodium-rich effluent from the regeneration is discarded after, if desired, residual ammonia has been recovered by flash distillation.

Products obtained from a preferred Gd catalyst and from two other, less preferred, catalyst types are shown in Table 22. One of the two less preferred catalysts was obtained by activation (as in Example VII but with 8 hours at 400C. to insure good NI-I removal) of a highly (16 cycles) ammonium-exchanged type Y zeolite (to produce HY catalyst). The l-IY catalyst produced only about one-fourth as much alkylate, together with more C,,* and C and less C,,, as its cerium counterpart.

The other less preferred catalyst was prepared by activation of a l6-cycle cerium exchanged, 16-cycle ammonium-exchanged sodium X zeolite (to produce CeI-IX catalyst). In comparison with CeHY catalyst (run 664) the CeHX catalyst produced an appreciably smaller C paraffin yield. An Analysis of this paraffin product showed 23.9 mole percent to be isopentane (which is 2 to 4 times the isopentane usually found in alkylate produced by CeHY catalyst). Accordingly, the C paraffin in the alkylate producedv by the CeI-IX was only 59 mole percent compared with about percent for CeHY.

Runs 628 and 674 were made with catalysts prepared by an exchange procedure similar to that of Example IV and activated as in Example VII (except that for the run 674 catalyst helium was substituted for air), but wherein gadolinium nitrate was used instead of cerium nitrate in the exchange solution. The resulting novel Gd-alumino-silicate, upon activation, produced a novel catalyst which is very useful for hydrocarbon conversion, for example, see Table 22. GdHY zeolite, which can be prepared by activation of a crystalline GdNILY (or GdNaI-INI-LY) zeolite (e.g. obtained by Gd-cation exchange of highly ammonium-exchanged sodium Y zeolite), is also useful as an alkylation catalyst.

In the Gd alumino-silicate catalyst, at least 25 percent and, preferably, at least 40 percent of the electronegativity associated with the alumino-silicate framework is satisified by cations of gadolinium or of its oxides or hydroxides. When the Gd catalyst contains less than one alkali metal cation (e.g. Na) for every 4 aluminum atoms in the alumino-silicate framework, the catalyst is especially useful for such hydrocarbon conversion reactions as isomerizing polycyclic aromatic hydrocarbons, paraffin-olefin alkylation and the cracking of gas oil. Preferably, the alumino-silicate zeolite is crystalline and is chemically characterized by the em pirical formula M (AIO (SiO ),,.(I-I O) where x, y and z are integers, the ratio x/y being from 1.0 to 0.2 and where M is chosen from at least one of the following groups:

l. at least one Gd cation for every 12 atoms of aluminum in the alumino-silicate framework of said zeolite;

2. at least one cation of Gd( OI-I) for every 8 atoms of aluminum in the alumino-silicate framework of said zeolite;

3. at least one cation of Gd(Ol-I) for every 4 atoms of aluminum in the alumino-silicate framework of said zeolite;

4. a combination of the members of at least two of the above groups;

and wherein the balance of the cations necessary for electronic equivalency comprises H" or cations of metals, metal oxides or metal hydroxides and wherein there is less than one alkali metal cation for every four atoms of aluminum in the alumino-silicate zeolite, more preferably, less than one alkali metal cation for every ten atoms of aluminum.

The Gd zeolite can contain as such additional cations, the cations of magnesium, aluminum, silver, nickel, zinc, cerium, lanthanum and mixtures of these cations. In such catalysts it is preferred that at least one such cation is present for every 20 atoms of aluminum in the alumino-silicate framework of said zeolite.

For most hydrocarbon conversions, the ratio x/z in the empirical formula of the zeolite should be in the range of 0.25 to 2. If excess water is present, the zeolite should be activated by heating according to the procedure disclosed in the aforementioned applications of Kirsch, Bannby and Potts. If the zeolite is deficient in bound water, water can be added, as by exposure to steam in air or nitrogen.

As used herein, the term framework, in reference to the alumino-silicate portion of the zeolite (which can be crystalline or amorphous), excludes those aluminum,

ions which are in exchange positions and which are neutralizing some of the negative charge associated with .the aluminum atoms in the alumino-silicate tetrahedra of the zeolite. Note that aluminum in the alumino-silicate framework can be either trigonal or tetrahedral.

For such reactions as reforming, aromatization, hy-

TABLE 1 Exchanged Zeolite Catalysts Chemical Composition of Activated Equilibrated Ammonium-Only Catalyst Catalyst: 16 Exchange Cycles with Nl-LNO; solutes, Dry Air Medium, Rotary Kiln Catalyst No. Activation Conditions Weight Percent TIL Na-Eguivalent Moles" Maximum Temperature F Time**** Na N [-1 Na NH, E

Base NaY Zeolite 9.51 24.32 0.414 0.414 Base after N1! Exchange 1.04 5.50 23.76 0.045 0.393 0.438 Experiment A Run No.

A-] 150 30 1.01 5.51 24.63 0.044 0.394 0.438 A-Z 450 0 1.03 5.28 24.88 0.045 0.377 0.422 A-3 450 60 1.07 4.72 25.39 0.047 0.337 0.384 A-4 750 0 1 2.88 26.14 0.043 0.206 0.249 A-5 750 60 1 1.98 26.27 0.047 0.141 0.188 A-6 750 120 1 0.84 27.26 0.049 0.060 0.109 A-7 750 180 l 0.57 27.58 0.046 0.041 0.087 A-8 750 240 1 0.54 27.62 0.047 0.039 0.086 Experiment B B-l 150 1. 5.42 24.54 0.045 0.387 0.432 8-2 450 0 1. 5.04 25.07 0.045 0.360 0.405 8-3 450 1. 4.74 25.17 0.050 0.339 0.389 8-4 572 0 1 4.41 25.44 0.050 0.315 0.365 13-5 752 0 1 3.33 26.17 0.050 0.338 0.288 13-6 932 0 1 0.48 27.43 0.051 0.034 0.085 B-7 1112 0 1 0.14 27.65 0.051 0.010 0.061 8-8 1292 0 1 0.13 25.19 0.050 0.009 0.059 B-9 1292 120 l 0.13 25.57 0.056 0.009 0.065

TlL True ignition loss corrected for ammonium. Na Equivalent moles, moles/ g. ignited catalyst (TIL). Molar ratio Na,O/AI,O, was 0.98. Molar ratio Si(),/Al,0 was 4.70. Time. in minutes. at indicated maximum temperature.

TABLE 2 Exchanged Zeolite Catalysts Chemical Composition of Activated Ammonium Cerium Catalysts Activation Conditions: Rotary Kiln, Dry Air, Ambient pressure, Programmed Temperatures, Air rate 0.6SCFM Activation Conditions L01 Moles Run No. Max.Temp.F Time"* 11,0 Na Ce Nl-lf H O Experiment C O! 150 30 17.21 0.037 0.025 0.354 0.937 C-2 450 0 10.25 0.037 0.054 0.379 0.523 C-3 450 60 5.21 0.038 0.068 0.394 0.228 C4 750 0 4.05 0.038 0.043 0.371 0.186 C-5 750 60 3.38 0.034 0.020 0.350 0.169 C-6 750 3.56 0.036 0.014 0.345 0.186 C-7 750 180 3.09 0.033 0.009 0.336 0.163 C-8 750 240 3.40 0.035 0.009 0.337 0.180 Experiment D D-l 30 19.58 0.038 0.056 0.381 1.044 D-2 450 0 13.18 I 0.042 A 0.056 0.373 v 0.721 D-3 450 7 60 6. 89 01038 0.056 0.375 0.333 D-4 750 0 4.89 0.039 0.054 0.388 0.222 D-5 750 60 3.92 0.038 0.031 0.365 0.189 D-6 750 120 3.80 0.038 0.041 0.375 0.174 D-7 750 3.76 0.037 0.014 0.352 0.197 D8 750 240 3.47 0.040 0.010 0.352 0.183 Experiment E E] 150 30 15.09 0.037 0.051 0.376 0.796 E-2 450 0 9.76 0.043 0.051 0.387 0.497 E-3 450 60 5.08 0.042 0.057 0.370 0.230 E-4 572 4.84 0.043 0.057 0.396 0.216 E-S 752 4.08 0.041 0.049 0.384 0.182 E-6 932 3.04 0.040 0.012 0.341 0.157 E-7 1112 2.70 0.043 0.009 0.347 0.127 E-8 1292 0 2.24 0.045 0.009 0.355 0.116 E-9 1292 120 1.66 0.034 0.009 0.340 0.083

' L01 Loss an ignition (includes ammonium) Moles/100 g ignited catalyst (TIL) Time, in minutes at indicated maximum temperature.

' 'TXB'LE"Eiiiitrfiifiiiiififidi clmfisfi' Water-cerium ratio for ammonium-cerium exchanged zeollte catalysts activated at constant temperature for diflerent times Basis of data: Moles ion/100 g. anh drous base 3 10NH4+ exehangies followed by 16 e exchanges Activation con tions: Rotary kiln, dry air, ambient pressure, programed temperatures, air rate=0.6 s.c.f.m.

CGKOH) Time at Non-Ce 112m Total 13.0 Temp. temp. non-Ce Total for Ce H Run N0. F.) (min) A 1 SiOH Na+ N 4+ H20 H20 Ge (moles) Ce Experiment 0:

Mean of last five values 1. 006

Experiment D:

D-?. 450 60 0. 035 0. 018 0. 038 0. 028 0. 084 0. 333 249 2. 649 750 0 0. 022 0. 011 0. 039 0.027 0. 077 0. 222 o 0. 09s 1. 480 750 60 0. 045 0. 022 0. 038 0.016 0. 076 0. 189 0 113 0. 099 1.142 13 6. 750 120 0. 035 0. 018 0. 037 0. 076 0. 076 0. 174 0 098 O. 099 0. 990 D-7- 750 0. 058 0. 029 0. 037 O. 007 0. 073 0. 197 0. 124 0. 100 1 240 D-s 750 240 0.058 0. 029 0. 040 0. 005 0. 074 O. 183 109 0 101 1 079 Mean of last five values 1. 186 Mean of last four values 1. 112

1 A=[(Mo1ar equivalent Na+ in Na Base) (Molar equivalent of measured ions in eata1yst)l/100 g. anhydrous base.

evolved on ignition at 1,800 F 2 Non-CeHzO calculated as 2Si OH-VlHgO and ZNH4+- 1Hg0.

3 Anhydrous base=ignited catalyst to which is added as NHU', NH;

Exchangcd Zeolite Catalysts Water-cerium Ratio for Ammonium-Cerium Exchanges Zeolite Catalysts Activated at Different Temperatures Basis of Data: Moles ion/ 100 g anhydrous catalyst Catalyst: lfiNl-l, exchanges followed by l6Ce exchanges Activation Conditions: Rotary kiln, Dry air, Ambient pressure, Programmed temperatures, Air Rate 0.6 SCFM Time at Total 11,0 Temp Temp. Non-Ce 11,0 Non-Ce Total for Ce H,O/Ce Max. Run No. (F) (min) A" SiOH Na NH. 11,0 11,0 Ce (moles) Ratio 01-1 E-3 450 60 0.044 0.022 0.042 0.028 0.092 0.230 0.138 0.090 1.533 106 E-4 572 O 0.018 0.009 0.043 0.028 0.080 0.216 0.136 0.099 1.375 100 15-5 752 0 0.030 0.015 0.041 0.024 0.080 0.182 0.102 0.098 1.041 84 15-6 932 0 0.073 0.036 0.040 0.006 0.082 0.157 0.075 0.097 0.733 77 15-7 11 12 0 0.072 0.036 0.043 0.002 0.081 0.127 0.046 0.098 0.470 59 E-8 1292 0 0.069 0.034 0.045 0.000 0.079 0.116 0.037 0.100 0.370 54 15-9 1292 120 0.083 0.042 0.034 0.000 0.076 0.083 0.007 0.009 0.077 39 "'A [(Molar equivalent Na in Na-Base)-(Molar equivalents of measured ions in catalyst" (100 g anhydrous base "'NomCe H,O calculated as 2Si0H- 1H,O 8L 2NH 1H,O. Anhydrous base ignited catalyst to which is added. as N11 the NH, evolved on ignition at 1800F.

TABLE 5 ISOBUTANE-BUTENE-Z ALKYLATION WITH ZEOLlTE CATALYST Yield based on olefin charged C Paraffin Dist, Mole 3,839,228 33 34 TABLE 5-Continued 4 ISOBUTANE-BUTENE-Z ALKYLATION WITH ZEOLITE CATALYST Example No. V111 IX X111 X111 X111 t-Butyl n-Propyl n-Butyl Adjuvant None None Chloride Chloride Chloride Trimethylpentanes 88.2 74.0 82.4 88.1 85.0 Dimethylhexanes 1 1.8 24.6 16.6 11.9 14.9 Methylheptanes 0.0 1.5 1.1 0.0 0.1

TMP/DMH.r Ratio 7.47 3.01 4.98 7.38 5.71 2.2.4 in TMP** 26.9 21.0 25.0 23.0

In Ex. X111 halide concentration= 1.6 millirnole/mole total hydrocarbon charged. 80C.. 250 psig.. i-Crane/Cr ene 14.9 molar (min.). 3.67 hr. 16NH 16Ce3, -Cata1yst (10.13% Ce. 0.68% Na-before 400C. max. 37% at 1800V4 F d 0 activation) with an ignition 1oss= 24.37% at 1800Rz Feed introduced into bottom of .lerguson gauge.

* One product gas sample was lost. Some isopentane thereby not accounted for. and the C5* yield and distribution Mole percent 2.2,4-trimethy1pentane in total trimethylpentanes.

" Mole ration trimethylpentanes to dimethylhcxanes.

Mole percent 2.2.4-trimethy1pentane in total trimethylpentzmes.

TABLE 9 lSOPARAFFIN-OLEFIN ALKYLAT ION WITH ZEOLITE CATALYSTS CCl as Adjuvant 80C.. i-C aneIC ene-Z 15 (min.), 3.67 hr., Nl-lf. Ce*-Type Y Adjuvant Type TBC TBC TBC TBC" CCI & TBC TBC & TBA*'* CCI. Technique Con- Pulse Pulse Pulse Continuous Continuous Contrntinuous uous Amount, mmole/m 0C 42.6 28.4 30.1 30.1 30.1 CCl. 30.1 TBC 30.1 20.2 TBC 30.1 TBA Run Number 570 614 606 600 630 632 688 C Paraffin Yield, Wt. 0C 162.1 150.0 193.4 176.3 141.1 150.1 178.5 C,, Unsaturates, wt. 0C 0.00 0.00 0.04 C," Paraffin Distribn.. mole C 9.1 4.6 7.3 5.8 4.1 5.0 5.8 Cg 73.2 76.3 i 71.1 72.3 71.5 72.2 74.9 C, 7.3 7.3 7.1 7.1 6.8 7.0 7.5 C 6.4 5.9 5.8 5.7 5.2 5.7 5.4 C, 4.0 5.9 12.4 10.2 6.4 C Paraffin Distribution TMP 86.0 88.4 87.1 87.8 88.0 88.2 87.9 DMH, 13.7 11.6 12.9 12.0 11.9 11.8 12.1 Ml-l, 0.3 0.0 0.0 0.2 0.0 0.0 0.1 TMP Distribution 'Perylene (from CCI presorhed on catalyst, TBC added continuously CCl presorbed on catalyst. TBC added continuously 'TBA t-butyl alcohol. TBC t-butyl chloride TABLE 10 Paraffin lsobutane 150121;"?116 lsobutane lsobutane n-Butane lsobutane lsobutane 04 2 M lhy| 2 M thyl 0*! #0 iii iii 88 Olefin butene-2 butene-Z Butane-2 Butene-l Butene-l Butene-Z Butene-2 Temperature C. 120 120 120 120 80 80 80 Pressure. psig. 460 485 455 455 250 250 250 Catalyst Wt.% Na (ignited) 1.68 1.11 1.11 1.38 0.76 0.76 0.76 Wt.% Ce (ignited) 6.8 8.7 8.7 12.4 13.5 13.5 13.5 C,* 'Paraffin Yield 28.6 49.0 51.8 119.7 25.6 135.0 132.0 Wt.% Olefin Chg. V C Unsaturate 31.2 15.4 0.5 2.8 1.6 1.88 0.26

Yield, Wt.% Olefin Chg. Cf Paraffin Dist.. Mole C; 32 5 29.2 4 2 9.7 26.6 14.6 8.0 C 32 6 36.6 82 8 55.0 25.6 69.3 69.0 1 15 6 10.3 6 2 12.0 2.0 6.7 6.1 C 15 2 10.3 5 2 11.4 2.0 5.5 5.2 C 4 0 13.6 1 6 11.9 43.8 4.0 11.7

TABLE 10-Contmued Paraffin lsobutane lsobutane lsobutane lsobutane n-Butahe' lsobutane lsobutane 2 M thy] 2 M thyl it *4 *ikl 84 Olefin butene-2 butene-Z Butene-Z Butene-l Butene-l Butene-2 Butene-Z C, Paraffin Dist., Mole Trimethyl- 71.2 74.7 63.8 75.7 33.7 85.4 88.0

pentanes Dimethyl- 26.4 24.3 36.4 23.1 65.6 14.6 12.0

hexanes Methylheptanes 2.4 1.0 0.7 1.2 0.7 0.0 0.0

'=2.4 X 10 mole tertiary butyl chloride used as adjuvant per mole of n-butane. I "=Catalyst activated at 500C. (all other runs at 400C.) =Feed introduced at top of .lerguson gauge. '=Feed introduced at bottom of Jerguson gauge.

TABLE 1 1 Ex. Ex. Ex. Ex. Ex. Ex. Ex. Cutulyst Prep. 11 IV [V V11" XV" XV" 1V Temperature C. 120 120 120 80 80 80 80 Pressure. psig. 500 500 500 250 250 250 250 Wt.% Na (ignited) 0.26 1.38 0.3 0.6 0.82 0.9 0.76 Wt.% Cc (ignited) 12.4 13.5 1.72 13.5

Wt.% La (ignited) 12.3 Wt.% N (before 6.42 0.98 0.66 5.20 1.18 0.57 0.86

activation) Wt.% Ignition 30.25 24.24 25.84 28.41 25.25 24.95 24.70

Loss Wt.% C; Paraf- 109.5 119.3 75.3 26.0 68.4 142.4 132.0

finYield" Wt.% C Unsatu- 2.8 5.6 1.1 10.9 0.13 0.13 0.26

rate Yield C Paraffin Dist. Mole C; 19.7 11.5 11.2 27.2 5.4 3.6 8.0 C, 42.5 50.3 72.0 57.9 81.0 60.0 69.0 9.5 9.0 8.6 5.8 5.9 4.1 6.1 C 9.7 8.4 2.2 5.8 4.4 3.1 5.2 C; 18.6 20.7 6.0 3.3 3.2 29.2 11.7 C Paraffin Dist.

Mole Tri- 72.0 73.1 75.0 55.1 89.0 88.4 88.0 methylpentanes Mole Di- 27.2 25.7 23.8 41.4 11.0 11.6 12.0 methylhexanes Mole Methyl- 0.7 1.2 1.2 3.5 0.0 0.0 0.0 heptanes Mole TMP/DMH, 2.64 2.84 3.15 1.33 8.06 7.65 7.30

=Based on weight of olefin charged.

"=t-Butyl chloride adjuvant. Olefin and parafl'tn entered bottom of .lerguson gauge.

"'=Catalyst prepared from La(NO,) solution.

""=Catalyst prepared from mixed rare earth nitrate solution and analyzed 13.8% totad rare earth metals (ignited).

TAEIIFTi Catalyst Content "Use of the magnetic drive on the reactor possibly increased this yield as much as 15; over what it would have been with the same packed drive used for the other runs. Ewn at (112415 98%). its yield vastly exceeds that from La(NO,),.

TABLE 13 ISOPARAFFlN-OLEFIN ALKYLATION WITH ZEOLlTE CATALYSTS Rare Earth Cation and Anion Effects on Catalysts 80C., 250 psig., i-C -ane/C ene-2 14.9 (min.). 3.67 hr. 1.0 g. t-Butyl Chloride Salt for Exchange Ce(NO;)= CeCl, RE(NO,), RECI, La( N01); LaCl, Catalyst Composition Sodium, wt.% (ignited residue basis) 0.76 0.78 1.17 0.89 0.82 1.09 Rare Earth, wt.% (ignited residue basis) 13.5 12.9 14.2 11.1 13.1 1 1.9

3,839,228 37 mm m 38 TABLE 13 -Continued lSOPARAFFlN-OLEFIN ALKYLATlON WITH ZEOLlTE CATALYSTS Rare Earth Cation and Anion Effects on Catalysts 80C., 250 psig.. i-C.-aneIC ene-2 14.9 (min.). 3.67 hr. 1.0 g. t-Butyl Chloride Salt for Exchange Ce(NO,), CeCl, RE(NO,)= REC], La(NO,): LaCl, Catalyst Composition 5 Run Number (467-) 830 822 8 0 854 818 858 C, Paraffin, wt.% chg. 132.0 73.1 142.4 103.1 68.4 112.0 C, Unsaturates, wt. olefin chg. 0.26 0.15 0.13 0.77 0.13 0.16 C," Paraffin Distribution C mole 8.0 6.5 3.6 10.6 5.4 8.1 C do. 69.0 78.1 60.0 66.9 81.0 61.7 C do. 6.1 5.7 4.1 6.7 5.9 6.4 C do. 5.2 4.1 3.1 3.9 4.4 4.4 C, do. 11.7 5.5 29.2 11.9 3.2 19.5 C, Paraffin Distribution TMP, mole T 88.0 88.6 88.4 84.8 89.0 86.2 DMl-L mole 12.0 11.4 16.6 15.2 11.0 13.8 Ml-l mole 0.0 0.0 .0 0.0 0.0 0.0 'lMPlDMl-l Ratio 7.30 7.74 7.65 5.09 8.06 6.25

TABLE 14 ISOPARAFFlN-OLEFIN ALKYLATION WITH ZEOLITE CATALYSTS Catalyst Cerium Sodium Effects on Alkylation 80C., 250 psig.. i-C ane/C -ene-2 14.9 (min.). 3.67 hr. 1.0 g. t-Butyl Chloride Catalyst Composition Sodium. wt. (ignited residue basis) 0.23 0.76 1.68 2.76 1.68 1.24 Cerium, wt. (do.) 13.7"" 13.5" 12.8"" 13.0 8.3"" 2.0 Run Number (467-) 852 830 848 850 846 828 C; Paraffin, wt. o1efi n charge 7 135.2 132.0 115.4 118.9 a 62.7 26L c; Unsaturates, wt. olefin charge 0.32 0.26 0.42 0.77 4.52 10.85 C Paraffin Distribution CJ. mole 8.4 8.0 10.6' 10.1 19.1 27.2 C do. 66.0 69.0 63.4 72.8 64.1 57.9 C do. 6.6 6.1 6.7 7.2 7.4 5.8 C do. 4.9 5.2 5.5 5.7 6.0 5.8 C, do. 14.1 11.7 13.9 4.1 3.4 3.3 C Paraffin Distribution MP, mole 87.5 88.0 85.7 87.2 82.9 55.1 DMH mole 12.4 12.0 14.3 12.8 16.2 41.4 MH,,, mole 0.1 0.0 0.0 0.0 0.9 3.5 TMP/DMl-l, Ratio 7.08 7.30 6.00 6.80 5.10 1.33

"=By X-ray fluorescence. Others were by gravirnetry.

Helium and Hydrogen versus Air Activation at 400C. NH Ce- Type Y Base 80C. autogeneous pressure, i-C -ane/C -ene-2 15 (min.), 3.67 hr., 1.0 g. TBC

Activation Gas Air Air H He Run No. 654 656 658 660 Cf Paraffin Yield, wt.% 0C 142.6 139.7 148.8 160.6 Cf Unsaturates, wt.% 0C 0.00 0.05 0.00 0.14 C Paraffin Distribn., mole C 9.2 9.1 8 1 7 8 C; 66.8 66.1 69 2 70 5 C, 6.4 6.2 6 7 5 8 B 6.2 5.8 5 7 5 9 5 11.4 12 9 10 3 99, C, Paraffin Distribn.

T 85 6 86 4 86 7 87 5 DMH, 14.4 13.5 131 12 4 MH, 0.0 0.2 0 2 0 0 TMP Distribn. 

1. AN ALUMINO-SILICATE ZEOLITE, USEFUL AS A CATALYST FOR PARAFFIN-OLEFIN ALKYLATION, WHICH IS AT LEAST REPRESENTED BY THE EMPIRICAL FORMULA
 2. The zeolite of claim 1, wherein said rare earth metal consists essentially of cerium.
 3. The zeolite of claim 1 wherein the ratio x/y is in the range of 0.35-0.65.
 4. The zeolite of claim 1 wherein when said zeolite is analyzed by ignition at 1,800*F., from 0.5 to 6 molecules of water is obtained for each atom of a rare earth metal cation in said zeolite.
 5. The zeolite of claim 1 wherein the ratio x/z is in the range of 0.25 to
 2. 6. The zeolite of claim 4 wherein said rare earth metal consists essentially of gadolinium and wherein said zeolite is at least 50 percent crystalline and can adsorb benzene.
 7. The zeolite of claim 6 wherein said zeolite on an ignited basis contains less than 1 wt. percent Na, at least 14 wt. percent Gd, and has a Y framework.
 8. The catalyst of claim 1 wherein said zeolite has been heated at a temperature in the range of 600* to 700*C and upon ignition analysis at 1,800*F evolves less than 60 percent of the weight of water which can be evolved from a sample of said zeolite which has been equilibrated in air of about 50 percent relative humidity, at about 680*C for about 12 hours and then heated to 300*C for sufficient time that substantially no bound water can be evolved from said sample at 300*C.
 9. Crystalline zeolite Y containing at least one cation comprising cerium and containing no more than one cation of an alkali metal, the balance of cations necessary for electronic equivalence being provided by protons, for every nine atoms of aluminum in the framework of said zeolite.
 10. Crystalline zeolite Y according to claim 9 and which is acidic and substantially anhydrous.
 11. Crystalline zeolite Y according to claim 9 and containing at least one of the cations Ce 3, CeOH 3, CeOH 2 and CeO
 2. 12. Crystalline zeolite Y according to claim 9 and having a cation distribution of about 3-23 percent Na and about 49-70 percent Ce
 3. 13. The composition of claim 9 wherein said zeolite corresponds to about the formula 0.1Na2O:A2((NH4)2O):A3(H2O):0.7(Ce2/3O):Al2O3:4.7SiO2, where the sum of A2 and A3 is about 0.2. 